Approaches to UVing

When it comes to 3D modelling, there is that one task that everyone despises. UVing. A UV is the unwrapping process of a 3D model. The letters "U" and "V" denote the axes of a 2D texture because "X, Y and Z" are already taken up by the 3D model in spatial co-ordinates. The easiest way to think of a UV is to think of it like origami or paper crafting. If you were to take an origami crane and unfold it, that is effectively what a UV is. The purpose of this is to draw on 2D textures to give the 3D model life.

When it comes to the UV process, you are presented with a four square UV editor, this is your work space. The top right square is the only square that will have a texture, and all of the model's UVs must fit within this space. One of the more important things to keep in mind is having appropriate pixel density for each UV, especially if sharing the same textures among different models. The reason for this is if you have different pixel densities between models, you will have evident stretching and distortion of the texture compared to each other.

Maya has several UV editor options. One of the common tools to use is the Automatic UV feature, in which Maya attempts to layout UV shells in the best possible way in attempt to make life easier. Often after an automatic unwrap, the shells you are presented with can be....intimidating. One of the best things you can do is to separate all of the pieces and group them appropriately. For example, put all the door pieces in one area, all wall pieces in another etc.

There are several tools available in the editor window such as flipping shells around and cutting edges. Sometimes the unwrap moves things in less than ideal ways, and shifting them around is needed. One key thing to be mindful of is where 'seams' will be present in an unwrap/texture. Obviously due to the fact that it is a 2D image being wrapped around a 3D model there is going to be a connecting line somewhere. One workaround for this is to make sure that you use tillable textures, or to position seams in a location that can't really be seen, or would be believable such as the seams on clothing. You can 'sew' shell edges together to eliminate seams and piece together the appropriate sections. This is personally for me where I struggle at times, trying to layout and sew the right pieces together in the best possible way.

Finally, it is important to ensure you make maximum use of the space given to you in the texture square. Regardless of what's in it, the square will use the exact some amount of memory to read the image file, so may as well make the most of it!

#GDS210